Control



Oct. 23, 1951 G. J. MUCHER 2,572,651

CONTROL n Filed May ll, 1950 40 fg?. Z ,7 40 M f Patented Oct. 23, 1951 UNITED CONTROL George J. Mucher, Rochester, N. H., assignor to Clarostat Mfg. Co., Inc., Dover, N. H., a corporation of New York Application May 11, 1950, Serial No. 161,330

This invention relates to a structurally and functionally improved electrical control.

It is an object of the invention to furnish a device of this character which will be extremely compact and accordingly usable in locations where the space is quite limited.

A further object is that of providing a unit of this type which may be assembled with one or more additional units to furnish a multiple control; such assembly being readily capable of achievement.

Still another object is that of furnishing a control involving relatively few parts each individually simple and rugged in construction, such parts being capable of production by quantity manufacturing techniques and being moreover susceptible to ready assemblage by relatively unskilled labor to furnish a control operating over long periods of time with freedom from all difliculties.

With these and other objects in mind, reference is had to the attached sheet of drawings illustrating one practical embodiment of the invention and in which:

Fig. 1 is a side elevation of a pair of controls operatively coupled to furnish a single assembly;

Fig. 2 is a rear view of such control;

Fig. 3 is a sectional side view taken through a single one of the controls;

Fig. 4 is a plan view of the casing with the rotor or contact assembly removed therefrom;

Fig. 5 is a plan view of the cover with the rotor mounted therein; and

Fig. 6 is a sectional side view of a multiple control assembly as shown in Fig. 1.

The casing for the control preferably includes a body portion I conveniently circular in configuration and having an upstanding flange II which may be notched as indicated at I2. This casing is formed of di-electric material and may be provided with exterior ribs I3 in line with the notches I2. It may also have its base formed with a centrally weakened area indicated at I4 so that this portion of the casing may be removed or knocked out should it be desired to provide a multiple assembly. Disposed upon the base of the casing is a resistance member I conveniently in the form of a graphite coated strip preferably extending through almost 360 degrees. 'Terminals I6 and I1 are affixed to the ends of this resistance and in such affixing may also serve to maintain the resistance in position within the casing. A conducting ring I8 is mounted by the casing at a point axially spaced from resistance I5 and a terminal I9 may connect with this ring.

3 Claims. (Cl. 201-55) The foregoing arrangement of parts represents a preferred embodiment. It is, of course, obvious that the positions of the resistance I5 and ring I8 might be reversed or shifted in any desired manner to accord with accepted practice.

The casing cover 20 has a flange 2| from the edge of which projections 22 extend. These projections are of an area such that they may be accommodated within the notches I2 of the casing body. A bushing, 23, is carried by the cover and rotatably mounts a shaft 24 which, as shown, may be retained against axial displacement by a split ring and groove structure 24. The inner end of the shaft 24 is reduced and of preferably non-circular configuration as indicated at 25. It extends through a limiting member 26 and any suitable number of layers of di-electric material 2l and 28. The limiting member 26 is formed with an outwardly extending portion 29 as shown especially in Fig. 5. The outermost layer or member 28 is restrained from displacement with respect to the end portion 25 of shaft 24 by means of a retaining element 30 of any suitable design. This outermost layer or member 28 is also formed with an extension 3| which serves to mount a contact member 32 conveniently by means of clips 33. Arms 34 and 35 extend from member 32 and project into different planes. Accordingly, arm 34 may traverse contact ring I8 when the cover is in position upon the body of the casing and arm 35 may traverse the surface of resistance I5. Cover 20 preferably presents an inwardly extending stop portion 35 for cooperation with the projecting part 29 of the limiting member 26. Therefore, a limiting structure is furnished which prevents the rotor or contact assembly from being shifted beyond predetermined and desired points.

To retain the cover in position upon the casing body, a clamping member may be employed which conveniently embraces a ring-shaped body 36 to bear against the outer face of the cover. A locating pin or extension 36 may form a part of that body to prevent rotation of the control unit. From that body legs 3'I extend in a lateral direction to terminate in securing or foot portions 38. The latter may bear against the outer face of protuberances 39 formed on the rear face of the casing body. Conveniently legs 3'I are also formed with longitudinally extending channels 40 which accommodate rib portions I3. It is apparent that with a securing member of this type properly applied, a separation of the parts will be prevented and the securing member will also be prevented from having relative movements with respect to those parts.

A control embodying the foregoing construction will be extremely compact and may be produced in very small sizes. Accordingly, such a control may be employed in locations where it would not be feasible to utilize controls of ordinary dimensions. One of the main factors permitting of the control being produced in such reduced size is that the several parts of the same are largely disposed in axially spaced positions with respect to each other, rather than being disposed in concentrically spaced positions as in the case of an ordinary control. It is of course apparent that as shaft 2li turns it will swing the assembly mounted by the reduced end portion of such shaft. With movements of this type occurring, contact arm will traverse resistance I5 and contact arm 3d will traverse ring I8 to thus establish the desired circuit and control therefor.

In certain instances it might be desired to furnish an assembly embracing any desired number of these controls. In order to not unnecessarily confuse the illustration, merely a pair of such controls have been shown in Fig. 6. In that view the numeral 4I indicates a shaft of a greater length than shaft 2li and having a reduced end portion 42. The weakened portion Ill of one casing section is knocked out and the end of the shaft is extended through the same. lSuch end is conveniently encircled by a bushing and spacing member 13. A securing and retaining unit 44 of greater length than the unit employed in av single control is utilized as shown in Fig. 6. This has the ends of its legs bearing against the extensions 39 of the rearmost casing and its ring-shaped body bearing against the cover 20. The grooved or channelled portions of the legs accommodate the ribs I3. Therefore, relative rotation of the parts is prevented. As will also be seen in this View, the extended portions 39 of the outermost or right hand casing extend into the notches I2 of the rear or innermost casing. Consequently these parts are also prevented from moving with respect to each other and the entire assembly is retained as a unit regardless of Whether that assembly embraces two or more controls.

Thus, it is apparent that a control is furnished which includes a body capable of having a very reduced diameter. Such reduction, however, is not achieved at the sacrifice of any of the desirable operating characteristics of the control. Rather, the resistance I5 being traversed by the arm 35 and the contact ring I8 being engaged by the arm 34, the rotation of the operating shaft will produce precisely the desired results. Therefore, an electrical apparatus of which the control forms a part may be quickly adjusted so that its controlled circuit embodies the desired electrical potential.

From the foregoing it is obvious, that among others, the several objects of the invention as specifically aforenoted are achieved. It will be apparent that numerous changes in construction and rearrangement of the parts might be resorted to without departing from the spirit of the invention as defined by the claims.

I claim:

1. In a control a clamping member for retaining a casing and cover therefor in assembled position, said clamping member including a body to bear against the outer face of the cover, laterally extending legs spaced from each other and integral with said body and foot portions integral With said legs adjacent the outer ends of the latter, said foot portions being engageable with that face of the casing which is opposite the face engaged by said cover.

2. In a control a clamping member for retaining a casing and cover therefor in assembled position, said clamping member including a body to bear against the outer face of the cover, laterally extending legs spaced from each other and integral with said body and foot portions integral with said legs adjacent the outer ends of the latter, said foot portions being engageable with that face of the casing which is opposite the face engaged by said cover and the inner faces of said legs being formed with channels to accommodate rib portions extending outwardly from a casing to which said clamping member is applied.

3. In a control a clamping member for retaining a casing and cover therefor in assembled position, said clamping member including a body to bear against the outer face of the coverLlegs, presenting inner and outer ends, extending laterally from said body and having their inner ends affixed thereto, said legs being spaced from each other along the length of said body, foot portions fixed with respect to the outer ends of said legs and extending inwardly and laterally therefrom to be engageable with that face of the casing Which is opposite the face engaged by said cover and said legs providing surfaces to lie adjacent the outer face of said casing to which said clamping member is applied.

GEORGE J. MUCI-l'ER.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 2,020,000 Schellenger Nov. 5, 1935 2,120,651 Schellenger June 14, 1938 2,389,750 Turner et al Nov. 27, 1945 2,512,745 Kebler June 27., 1950 

